采用共沉淀法制备Ni_0.4Fe_0.2Mn_0.4(OH)₂前驱体并将其配钠煅烧为O3-NaNi_0.4Fe_0.2Mn_0.4O₂正极材料,研究pH对前驱体物化性质及正极材料电化学性能的影响。结果表明,随着pH的增加,前驱体二次颗粒粒径减小,Ni元素质量分数升高,相应正极材料二次颗粒粒径减小,首次放电比容量增加。2.0~4.0 V的电压范围内,pH=10.0下制备前驱体配钠煅烧后的NaNi_0.4Fe_0.2Mn_0.4O₂正极材料表现出最优循环性能,1 C下循环100次后容量保持率为75.75%;pH=10.6下制备前驱体配钠煅烧后NaNi_0.4Fe_0.2Mn_0.4O₂正极材料表现出最优倍率性能,5 C下放电比容量为87.07 mAh/g。

Ni_0.4Fe_0.2Mn_0.4(OH)₂ precursor is prepared by co-precipitation method,and calcined together with sodium to O3-NaNi_0.4Fe_0.2Mn_0.4O₂ anode material.The effects of pH on the physical and chemical properties of precursor and electrochemical performance of anode material are studied.Results show that with the increase of pH,the size of secondary particles of precursor decreases,the mass fraction of Ni element increases,the size of secondary particles of the corresponding cathode material decreases,and the specific capacity of the first discharge increases.NaNi_0.4Fe_0.2Mn_0.4O₂ cathode material prepared from the precursor calcined with sodium at a pH of 10.0 shows the optimal cycling performance within the voltage range of 2.0-4.0 V.The capacity retention rate of the precursor is 75.75% after 100 cycles at 1 C.NaNi_0.4Fe_0.2Mn_0.4O₂ cathode material prepared from precursor calcined with sodium at a pH of 10.6 shows the optimum multiplicity performance,presenting a specific discharge capacity of 87.07 mAh·g^-1 at 5 C.

何一芃(1995-),男,硕士生,研究方向为钠离子电池正极材料,21216022271@stu.csust.edu.cn;李灵均(1984-),男,博士,教授,研究方向为新能源材料与器件,通讯联系人,lingjun.li@csust.edu.cn。